Refrigerating apparatus



p 1935- E. HEITMAN 2,013,515

REFRIGERATING APPARATUS Filed Sept; 25, 1952 2 Sheets-Sheet 1 IN VENTOR. 0 M9190 lienwmv ATTORNEY.

Sept. 3, 1935.

HEITMAN REFRIGERATING APPARATUS Filed Sept. 25, 1952 2 Sheets-She et 2 IN VENTOR. EDWQQD #67709 9 ATTORNEY.

Patented Sept. 3, 1935 UNITED STATES PATENT OFFICE asmreaaumc APPARATUS Edward Heitman, Detroit, Mich., assignor to Kelvinator Corporation, Detroit, Mich a corporation of Michigan Application September 23, 1932, Serial No. 634,505

' 4 Claims. (01. 62-126) exposed to the medium surrounding the evap-- 15 orator so as to be very efiective-in the absorption of heat from said medium;

Another object is to provide a refrigerant evaporator which is inexpensive to make, simple in construction and which is constructed of parts 20 which are easily manufactured and assembled.

Another object is to provide an improved refrigerant evaporator which is particularly'adapted for refrigerating large show cases,-and the like, and which occupies a relatively small space in 25 the case but is very effective in the absorption of heat therein.

Further objects and advantages of the present invention willbe apparent from the following description, reference being had to the accompany- 30 lng drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a diagrammatic representation of a I embodying features of refrigerating apparatus as my invention;

Fig. 2 is a view in cross section, taken along the line 2-2 of Fig. 1;

Fig. 3 is a view shown partly in elevation and partly in cross section of a cooling element em- 40 bodying features ,ofmy invention;

'Fig. 4 is a' view in cross section, taken along thelineHofFig.'3;.

Fig. 5 is a front view in elevation of a modified form of 'refrigerating apparatus embodying features of my'fiivention;

Fig. 6 is a view shown partly'in elevation and partly -in cross section of the cooling elementshown in the cabinet in Fig. 5; so Hgflisaviewincrosssectiomtakenalongthe line 1-1 ofFlg. 6; and Fig.8isaviewshowninperspectiveofthe cooling element shown in Fig. 5 removed from the cabinet.

as Referring to the draw. the numeral a designates a refrigerator cabinet of the well known type used for displaying foods The cabinet 20 I is provided with an insulated display compartment 22. Within the compartment 22, I have disposed my improved refrigerant evaporator or cooling element 25, for cooling the circulating air therein. The evaporator extends throughout substantially the entire length of compartment 2|. The cooling element 25 is operatively connected to a refrigerant condensing unit 21 by a liquid 10 supply conduit 29 and a vapor return conduit 30.

In refrigerant evaporators, the rapidity with which the refrigerant evaporates, and consequently the amount of heat which can be absorbed from the circulating air, depends upon the area of surface available for the transfer of heat between the air and refrigerant.

In accordance withmy invention, 1 have pro- 1 'v'ided a compact but large heat capacity refrig-' erant evaporator and one which has a'large area exposed to the medium surrounding theevaporator. This is particularly advantageous in the event it is desired to maintain in-a frozen condi tion certain frozen foods stored therein. As will be noted in Fig. 1', the cooling element is rela-.

, tively long, narrow and flat-like, and extends substantially from one end of the compartment 2| to the other. This cooling element is preferably constructed of sheet metal and includes an upper sheet metal member 35 and a lower sheet metal member 31 separated by'a flat sheet of metal 33 disposed therebetween. The upper sheet metal member and the lower sheet metal member are formed so as to cooperate with the flat sheet 19 to providejseparate chambers or headers ll and 42. Theupper sheet metal member 35 is provided with an upwardly extending bent portion M, which extends substantiallythe length of the cooling element and serves as a manifold for vaporized refrigerant. As will 'be noted in the 40 drawings. the top member 35 is provided with downwardly extending side walls I! having out wardly turned flanges I] which are securedto plate 39, and the bottom member 21 is provided 1 with upwardly extending'side walls It having outwardly extending flanges" '40 which are toplate 29. p p H v In order to provide the evaporator-{25 with a large heat I have provided a" plurality. of hollow, flat-like flnsil. P ferably constructed or sheet metal. As will be noted, the

, hollow fins il'are substantially rectangular in sbapeand are formed to provides substantial space for liquid refrigerant between the walls thereof. 'In using sheet metal material, the fins can be readily formed by drawing dies. The fins are secured to the sheet metal member 31 so as to be in open communication with the chamber 42; As shown, the fins 58 are arranged in spaced parallel relation, depending from the fiat bottom of the sheet metal member3'l, and extending substantially across the width of the cooling element and substantially throughout the entire length thereof. The sheet metal member 31' is provided with a plurality of transversely extending openings 41 about which the metal is pressed downwardly as at 52. Outturned flanges 54 are formed about the upper or open ends of the fins 50, which flanges are adapted to seat in the depression 48 and be secured to the sheet metal member 31 to provide a fluid-tight joint therebetween, Fins of this type, as well as the parts 35, 31 and 39, may

readily be manufactured by punching and stamping operation, which not only facilitate the manufacture thereof but greatly reduce the manufacturing and material cost. By providing fins of this type together with the provision of the refrigerant headers, there is a large liquid refrigerant area exposed to the medium surrounding the evaporator.

In assembling the cooling element, the fins 50 are inserted through the openings in the bottom wall of the header 42. The flange members 54 of fins 58 are then secured to the flanges 52 of sheet metal member 31, preferably by spot welding. After this takes place, the sheet metal member 31 and fins 58 are, as a unit, dipped soldered. This insures fluid-tight joints between the parts of said unit. The next step in the assembly of the cooling element is to weld, or otherwise suitably secure, the sheet metal parts 35, 31 and 39 together at their edges.

i In the cooling element 25, I employ two refrigcrants, one in the chamber 48, which is hereinafter called the primary refrigerant, and a secondary refrigerant in the chamber or header 42, which is in open communication with the hollow fins 50. Liquid refrigerant is supplied by the condensing unit to the header 8 through an inlet connection 80 connected to supply conduit 29 and vaporized refrigerant is withdrawn from the chamber 48 through an outlet'connection 82 however, that the plate 39 may be dispensed with and the evaporator operated with but one refrigerant.

Any suitable condensing unit: may be used for supplying refrigeration to the cooling element 25.

In the chosen illustration, the unit comprises, in general, a compressor 85, a motor 81 for driving the compressor, a condenser 89, and a high side' float III, which controls the flow of 'liquid refrigerant to the evaporator 25. The compressor withdraws the gaseous refrigerant from the evaporator through the vapor conduit 38, compresses the gaseous refrigerant and delivers it to the condenser wherein it is liquefied and from which it is delivered to the high side float 18. Preferably, the unit is intermittently operated. In order to control the operation of the motor 81, I have provided an automatic switch 15 which is actuated, for instance, in response to changes in temperature within the compartment 2| by means of a thermostatic bulb H which is associated with the switch. If desired, the switch may be made to operate in response to changes in pressures within the conduit 38 in the well known manner.

In Fig. of the drawings, I have shown my invention in connection with a household refrigerator, designated'in' general by the numeral 88-, for

cooling a food storage compartment 83. A cooling element or evaporator 85 is shown disposed within'the food storage compartment 83. This refrigerant evaporating element is similar in appearance to the evaporator previously described. However, in this instance, the evaporator is operated with but onerefrigerant, although it will be understood that primary and secondary refrigerating systems could also be used in this case.

The cooling element 85 is preferably constructed of sheet metal consisting of an upper sheet metal member 88, which is substantially fiat for supporting ice trays 89, and a lower sheet metal member 90, which is also substantially flat. The sheet metal parts 88 and 98 are formed to cooperate and provide a chamber or header 92 therebetween for containing refrigerant. An upwardly extending portion 93 is formed across the top of the upper member to provide a-manifold for vaporized refrigerant, which extends substantially longitudinally of the evaporator. The

upper sheet metal member 88 and the lower sheet metal member 90 are formed with outturned flanges 91 and 98 which are secured together, such as by welding, to provide the chamber 92 fluid-tight.

This cooling element is similarly provided with a large heat transfer surface by providing a plurality of hollow fins 99 secured to the sheet metal member 98. The fins 99, as shown, are in open communication with the chamber 92 and are adapted to contain a quantity of refrigerant and provide a large heat transfer surface between circulating air in compartment 83 and the refrigerant. The fins 99 are arranged in spaced parallel relation and extend substantially across the width of the cooling element and are attached thereto in the same manner as the fins of the previously described cooling element are attached.

The cooling element 85 may be operated by an intermittently operated condensing element, such as described and shown in Fig. 1 of the drawings. Gaseous refrigerant is withdrawn from the evaporator 85 through a vapor conduit I 81, and after being compressed and condensed is returned in its liquid state through pipe I89 tothe chamber 92 and the hollow fins 99 to again vaporize and absorb heat from the circulating air passing overthe large surface formed by the fins.

From the foregoing description, it will be apparent that I have provided a new and improved evaporator for refrigerating apparatus. With an evaporator of this type,-a relatively large food with a relatively large heat transfer surface is nevertheless as a whole, a small unit in comparison to the size compartment it is capable of refrigerating and consequently occupies'little of the space thereof. It will also be seen that I be made therein without departing from the. spirit of the invention or from the scope of the appended claims.

What I claim as my invention is 1. A sheet metal refrigerant evaporator forrefrigerating apparatus comprising, in combi nation, a pair of sheet-metal members secured together to provide a refrigerant header, and a numberof different sheet metal hollow refrigerant containing fins having outwardlyextending flange portions at one end thereof for securing said fins to said header, said fins being open at the flange ends for receiving refrigerant from said header and said flange portions being secured to said header on the inner side of said header.- I

2. A sheet metal refrigerant evaporator for refrigerating apparatus comprising, in combination, sheet metal material formed to provide a refrigerant header, and a number of different sheet metal hollow refrigerant containing fins having outwardly extending flangeportions at one end thereof for securing said fins to said header, said fins being open at the flange ends for receiving refrigerant from saidheader and said flange. portions being secured to said header on the inner side of said header.

'3. A sheet metal refrigerant evaporator for refrigerating apparatus comprising, in combination, sheet metal material formed to provide a flat elongated refrigerant header, and a number of different sheet metal hollow refrigerant containing flns hav'ing outwardly extending flange portions at one end thereof for securing said fins to said header, said fins being open at the flange ends for receiving refrigerant from said header and said flange portions beingsecured to said header forming a plurality of transverse refrigerant passages below the header on the under side of said header.

4. A sheet metal refrigerant evaporator for refrigerating apparatus comprising, in combination, sheet metal material formed to provide refrigerant headers for primary and secondary refrigerants, and a number of different sheet metal hollow refrigerant containing fins having outwardly extending flange portions at one end thereof for securing said fins to the header for secondary refrigerant, said fins being open at the flange ends for receiving refrigerant from said header and said flange portions being secured to said header on the inner side thereof.

EDWARD 

